Toilet overflow prevention system and method

ABSTRACT

A system for preventing overflow of a toilet includes a sensor, a processor and an actuator. The sensor senses a parameter caused by fluid dynamics within the toilet during a flush cycle. The parameter may involve vibration, sound, pressure, fluid flow rate or other detectible characteristics of the toilet. The processor uses information regarding the parameter that is gathered by the sensor to evaluate the condition of the flush cycle to determine if an impeded flush condition exists. In the event of an impeded flush condition, the processor directs the actuator to close a valve, which may be the toilet flapper valve in some embodiments. Also disclosed are methods for preventing toilet overflow, detecting an impeded flush condition and calibrating the system.

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/733,616, filed Apr. 10, 2007, scheduled to issue as U.S. Pat. No.7,636,959, which is a non-provisional application of, and claimspriority to, U.S. Provisional Patent Application No. 60/888,264, filedFeb. 5, 2007, and U.S. Provisional Patent Application No. 60/870,520,filed Dec. 18, 2006, the entireties of which are incorporated byreference herein and made a part of the present disclosure.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to toilets. More specifically,the present invention relates to an overflow prevention device for atoilet.

2. Description of the Related Art

Although significant advances have been made in toilet technology,particularly in reducing the amount of water needed for flushingpurposes, a satisfactory solution for preventing the overflow of atoilet in the event of a blockage of the toilet bowl, or associatedwaste plumbing, has not been achieved. Existing overflow preventiondevices, in order to provide acceptable reliability, are often complexand result in the devices having a high cost. Furthermore, existingoverflow prevention devices often include visible components, which canresult in a displeasing appearance.

SUMMARY OF THE INVENTION

Preferred embodiments of the present invention operate to prevent toiletoverflow in a cost-effective and reliable manner. In addition, preferredembodiments may be integrated into a toilet assembly during manufactureor retrofitted into an existing toilet, preferably with little or nomodification of the standard toilet. Embodiments intended forretrofitting in existing toilets desirably require a low level of skillto install.

An aspect of the present invention involves a toilet overflow preventionsystem for use with a toilet, including a sensor capable of detectingvibration of the toilet during a flush cycle. The sensor generates asignal indicative of the vibration. A processor receives the signal fromthe sensor and processes the signal to determine if the vibration isindicative of an impeded flush condition. If an impeded flush conditionis determined to exist, the processor generates a control signal. Anactuator receives the control signal from the sensor and in response tothe control signal operates to close a valve, which stops a flow ofwater within the toilet. The valve may be the flapper valve of thetoilet that controls a flow of water from the tank to the bowl of thetoilet.

Another aspect of the present invention involves a method for preventingtoilet overflow, including detecting a vibration of the toilet during aflush cycle and comparing a parameter of the vibration to a normal rangeof the parameter. The method also includes determining that an impededflush condition exists if the parameter is outside of the normal rangeand closing a valve to at least substantially stop a flow of waterwithin the toilet.

Still another aspect of the present invention involves a method ofcalibrating a system for detecting an impeded flush of a toiletcomprising sensing the value of a parameter of one or more normal flushcycles of the toilet and establishing a normal range for the value ofthe parameter using the sensed value. The method may also includestoring the normal range in a memory for comparison to a value of theparameter during subsequent flush cycles. The method may further includethe sensing being performed over a predetermined timeframe. The methodmay still further include the time frame being sufficient to include theentire push cycle of the toilet.

Another aspect of the present invention involves a method of determiningthe existence of an impeded flow condition of a toilet comprisingsensing a value of a parameter of a flush cycle caused by water dynamicswithin the toilet, comparing the sensed value of the parameter to anormal range of values for the parameter and determining that an impededflow condition exists if the sensed value is outside of the normalrange.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentinvention are described in connection with preferred embodiments of theinvention, in reference to the accompanying drawings. The illustratedembodiments, however, are merely exemplary and are not intended to limitthe invention. The drawings include the following nine figures.

FIG. 1 is a side, partial cross-sectional view of a toilet incorporatingan overflow prevention device including certain features, aspects andadvantages of the present invention. The toilet generally includes abase, defining a bowl, and a tank supported on the base. An interior ofthe tank communicates with the bowl through a passage.

FIG. 2 is a schematic illustration of the toilet and the overflow deviceof FIG. 1. The illustrated overflow device generally includes a sensor,a processor, and an actuator.

FIG. 3A is a representation of a sensor output as a function of time inthe event of a normal flush condition.

FIG. 3B is a representation of a sensor output as a function of time inthe event of an impeded flush condition.

FIG. 4 is a flow chart of a control method for a toilet overflowprevention system.

FIG. 5 is a flow chart of a control method for determining if an impededflow condition is present in the bowl of a toilet.

FIG. 6 is a flow chart of a toilet overflow prevention devicecalibration method.

FIG. 7 is a perspective view of an embodiment of an actuator of thetoilet overflow prevention device of FIG. 1 and FIG. 2. The actuator ofFIG. 7 is configured to shut the flapper valve of a toilet in responseto an appropriate control signal.

FIG. 8 is a perspective view of the actuator of FIG. 7 attached to atoilet overflow tube.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a preferred embodiment of a toilet overflowprevention system 10 incorporated within a toilet 12. The system 10detects when waste water is not properly emptying from the toilet,generally referred to herein as an impeded flush condition. Thedetection of an impeded flush condition advantageously occurs during aflush cycle, such that remedial action can be taken by the system 10during the same flush cycle. The system 10 is capable of stopping a flowof water within the toilet 12 to prevent an overflow situation inresponse to the detection of an impeded flush condition. Preferredembodiments of the system 10 detect a measurable characteristic orparameter caused by the effects of fluid dynamics during the flushcycle, such as vibration, sound, fluid flow rate or pressure, anddetermine if an impeded flush condition exists based on the measuredcharacteristic or parameter.

The toilet 12 preferably is of a conventional configuration and includesa base 14 and a tank 16 supported on the base 14. Although the overflowprevention system 10 is described herein in the context of such a toilet12 having a base 14 and a tank 16, the system 10 may be adapted for usewith toilets having alternative configurations, such as a monolithicconstruction, as will be appreciated by one of skill in the art in viewof the present disclosure.

The base 14 defines a bowl 18, which is configured to hold a volume ofwater 20. A siphon tube 22 connects the bowl 18 with a wastewaterplumbing system 24. The siphon tube 22 extends in an upward directionfrom a lower portion of the bowl 18 and then curves into a downwarddirection toward the lower end of the base 14 to meet the wastewaterplumbing system 24. Accordingly, the height of the upper curve 14 adetermines a normal water level W_(N) within the bowl 18.

Preferably, the tank 16 is of a hollow construction and defines aninterior space configured to hold a volume of water 20. The volume ofwater 20 in the tank 16 preferably defines a normal water level W_(T).Thus, the interior of the tank 16 is the divided into a water portionP_(W) and an air portion P_(A). Preferably, an open upper end of thetank 16 is covered by a lid 28.

Water 20 is evacuated from the tank 16 through an outlet 30 definedwithin a lower wall of the tank 16. Water 20 that passes through theoutlet 30 is delivered to the bowl 18 to initiate a flushing action. Forexample, in a washout-type toilet, water 20 from the tank 16 isdelivered to the bowl 18 through a passage 32 and gallery 34, as shown.The passage 32 extends generally vertically from the tank outlet 30 tothe gallery 34. The gallery 34 is oriented in a horizontal plane and,preferably, substantially surrounds the bowl 18 at its upper edge, orrim. Openings 36 permit water 20 to flow from the gallery 34 into thebowl 18. However, it will be appreciated by those of skill in the artthat the present system 10 may be used with any type of toilet,including siphon jet-type and blowout-type toilets, for example.

With additional reference to FIG. 1, the toilet 12 includes a primaryflush valve, or flapper valve 38. The illustrated flapper valve 38pivots between a closed position, wherein water 20 within the tank 16 issubstantially prevented from flowing through the tank outlet 30, to anopen position, wherein the water 20 within the tank 16 is permitted toflow through the tank outlet 30 and into the bowl 18 through the passage32 and the openings 36 of the gallery 34. The flapper valve 38 iscoupled to a handle 40 external to the tank 16, which permits a user toactivate flushing of the toilet 12 by utilizing the handle 40 to movethe flapper valve 38 to the open position. The flapper valve 38 isconfigured to close automatically once the water 20 within the tank 16is reduced to a particular level.

With continued reference to FIG. 1 and FIG. 2, the toilet 12 alsoincludes a tank fill mechanism 42 configured to refill the tank 16 withwater 20 from an external water supply source 44 after the tank 16 hasbeen emptied, or the volume of water 20 reduced, during a flush cycle.The tank fill mechanism 42 includes a filler valve 46, which istypically supported at a height above the lower end of the tank 16 by asupport structure 48. The filler valve 46 is configured to selectivelypermit water 20 from the water supply 44 to fill the tank 16 and,typically, the bowl 18.

The filler valve 46 supplies water 20 to the tank 16 and the bowl 18through a supply line 50. Preferably, the supply line 50 includes afirst branch, or tank supply branch 52 and a second branch, or bowlsupply branch 54. The tank supply branch 52 supplies water 20 directlyinto the interior of the tank 16.

The bowl supply branch 54 supplies water 20 to the bowl 18 through anoverflow tube 56. The overflow tube 56 includes an open upper end 58 anda lower end 60, which defines a discharge opening 62. The bowl supplybranch 54 supplies water 20 to an internal passage of the overflow tube56 through the upper end 58 and water is discharged through thedischarge opening 62.

Preferably, the upper end 58 of the overflow tube 56 is positioned abovea normal water level W_(T) within the tank 16. The discharge opening 62preferably is positioned below the flapper valve 38 to permit water 20within the tank to move into the bowl 18 through the overflow tube 56when the flapper valve 38 is in a closed position. Thus, the overflowtube 56 permits water 20 above a normal water level W_(T) to bypass theflapper valve 38 in the event that the water level within the tank 16rises above the upper end 58 of the overflow tube 56, for example, inthe event of a malfunction of the filler valve 46. The overflow tube 56also permits the filler valve 46 to supply water 20 to the bowl 18through the discharge opening 62 when the flapper valve 38 is in aclosed position.

The filler valve 46, in the illustrated arrangement, is controlled by atank water level sensor in the form of a float 64. Thus, the float 64establishes the normal water level W_(T) within the tank 16 by movingthe filler valve 46 to a closed position upon reaching a desired waterlevel W_(T).

With continued reference to FIGS. 1 and 2, the procedure of flushing thetoilet 12 generally comprises a flush cycle. The flush cycle can beconsidered to include a push cycle and a refill cycle. During the flushcycle the contents of the toilet bowl 18 are removed through the siphontube 22 by water 20 being passed from the tank 16 and entering the bowl18. In some embodiments, the flush cycle is initiated by actuating thelever 40 that opens the flapper valve 38 thus releasing water from thetank 16 to bowl 18. The initial part of the flush cycle in which theflapper valve 38 has been actuated by the lever 40 and is held open bythe buoyancy of the flapper valve 38 and movement of water 20 throughthe passage 32, is generally referred to as the push cycle. During thepush cycle a portion, and usually a substantial amount, of the water 20in the tank 16 is passed from the tank 16, through the passage 32 andthe gallery 34 and into the bowl 18. Thus, during the push cycle asubstantial amount of water 20 typically is passed from the tank 16 intothe bowl 18. During a normal push cycle, the rapid increase in waterlevel in the bowl 18 preferably creates a siphon effect that removes thecontents of the bowl 18 to the wastewater system 24 through the siphontube 22.

During the flush cycle, the push cycle preferably transitions to arefill cycle in which the flapper valve 38 closes and substantiallyreduces the flow of water 20 from the tank 16 to bowl 18 through thepassage 32. During a refill cycle the tank fill mechanism 42 refills thetank 16 and also refills the bowl 18 via the supply line 50 thatincludes a branch 54 that feeds water to the overflow tube 56 andsubsequently into the bowl 18. Once the water level in the tank 16 hasreturned to a normal level W_(T), as shown in FIG. 1, the float 64 shutsoff the filler valve 46 to end the refill cycle and thus end the flushcycle.

During the flush cycle, and particularly during the push cycle, the bodyof the toilet 12 is affected by the fluid dynamics caused by fluidmoving within the toilet 12. It has been discovered by the presentinventors that the fluid dynamics produce a number of measurablecharacteristics or parameters that can be used to detect if the flushcycle is normal. That is, by measuring the characteristics or parametersproduced by the fluid dynamics during the flush cycle, it is possible todetermine if the toilet 12 is in an impeded flush condition or if thetoilet 12 is in a normal flush condition.

Generally, an impeded flush is considered as any flush cycle in which ablockage or flow restriction causes a significant reduction in thenormal flow of contents from the bowl 18 to the wastewater plumbingsystem 24. Advantageously, certain embodiments of the present system 10can be adapted to respond to different levels of restriction to flow by,for example, correlating the level of the sensed characteristic orparameter with the level of the flow restriction. The impedance cancomprise content that is clogged within the siphon tube 22 or some kindof backup or clogging in or related to the wastewater plumbing system24. As will be appreciated by one skilled in the art, an impeded flowcan be caused by a wide variety of factors all of which cannot bepredicted.

In some embodiments, a normal flush is generally considered a flushcycle in which the contents of the bowl 18 can relatively freely flowout of the bowl 18 through the siphon tube 22 and into the wastewaterplumbing system 24 without substantial blockage or reduction of flow.Typically, under normal flush conditions, repeated flush cycles will notcause the water level in the bowl 18 to rise above, or remain above, thenormal water level.

With continued reference to FIG. 1 and FIG. 2, one embodiment of atoilet overflow prevention system 10 includes a sensor 70 that isconfigured to sense a parameter of the flush cycle. The sensor 70 is incommunication with an actuator 72 that is capable of initiating orimplementing a substantial or total reduction in the amount of water 20that can flow to the bowl 18 of the toilet 12. In some embodiments, thesensor 70 sends a control signal to a processor 78 to be processed bythe processor 78, which then transmits a control signal to the actuator72. The processor 78 includes a suitable algorithm that is configured todetermine if the signal is indicative of certain flow conditions andalso can include algorithms that decide if action should be taken inresponse to the signals. The processor 78 can also include variousalgorithms for calibrating the toilet overflow prevention system 10,which will be discussed in greater detail below.

The sensor 70, the processor 78 and the actuator 72 may be incommunication with one another by various different means. Such suitablemeans may include a hardwired cable or a wireless signal, such as an RFsignal or an acoustic signal. Other suitable methods for communicationbetween the sensor 70, actuator 72 and processor 78, as well as anyother components of the system 10, may also be employed. Althoughillustrated as separate components in FIGS. 1 and 2, the sensor 70 andactuator 72 could be part of an integrated assembly, in whichcommunication between the sensor 70 and actuator 72 could be integratedsuch that a separate wired or wireless communication link is notnecessary. Accordingly, as discussed further below, the sensor 70 is notlimited to the location (e.g., outside of the tank 16) shown in FIGS. 1and 2, but may be positioned in any suitable location in which thedesired flush characteristic or parameter may be adequately sensed.Thus, in some arrangements of the system 10, the sensor 70 may bepositioned within the tank 16.

The sensor 70 preferably includes necessary components to sense adesired parameter, create a signal indicative of the parameter that canbe communicated to other portions of the system 10. The illustratedsensor 70 includes a sensing element 74 that is configured to detect adesired parameter of a flush cycle of the toilet 12. The sensing element74 may be any suitable type of transducer that is capable of convertinga physical measurement into an electronic signal. Such a suitabletransducer can comprise vibrating elements (e.g., accelerometers),optical measurement elements, deflecting elements, capacitive,inductive, electromagnetic, strain gauge, piezoelectric, acousticalelements, etc., as will be appreciated by those of skill in the art. Insome embodiments, the sensor 70 may include or communicate with atransmitter 76 that is configured to transmit a signal to a processor78, or another portion of the system 10. In some embodiments, thesensing element 74 and/or transmitter 76 may be separate components fromthe sensor 70 or may be integrated with the sensor 70. Also, as will beappreciated by one skilled in the art, in certain configurations of thetoilet overflow prevention system 10, the transmitter 76 may not berequired.

In some embodiments, the system 10 or processor 78 may include a memory80 for storing certain protocols or parameters that may be used in theprocessing of signals from the sensor 70. The protocols or parametersmay be preprogrammed or they may be established during a calibrationprocess that is described in greater detail below.

The toilet overflow prevention system 10 also preferably includes anactuator 72 that, in some embodiments, may comprise a receiver 82 thatis configured to receive a signal from the sensor 70 that has beenprocessed by the processor 78. The actuator 72 may also comprise anelectromechanical device 84 that, in some embodiments, is arranged toclose the flapper valve 38 of the toilet 12. One exemplary embodiment ofthe actuator 72 is discussed in greater detail below with reference toFIG. 7 and FIG. 8.

As discussed above, the sensor 70 can comprise various different typesof sensors to detect various parameters of a flush cycle of the toilet12. Moreover, it may be desirable to utilize multiple sensors to provideadditional information to the system 10, such as a confirmation of animpeded flush condition to reduce the possibility of a falsedetermination of an impeded condition, which could possibly occur incertain circumstances using only a single sensor or single sensor type.In one embodiment, the sensor 70 detects vibrations of the toilet 12during a flush cycle. Such a detection of vibrations may comprisedirectly detecting vibrations of the toilet 12 or indirectly detectingvibrations of the toilet 12. On example of indirect detection of toiletvibration is to detect acoustical vibrations that are produced by thetoilet 12 during a flush cycle. On example of direct detection cancomprise detecting the physical displacement of the toilet 12 during aflush cycle, such as with accelerometers, strain gages, or othersuitable sensors.

In one embodiment, the sensor 70 is an accelerometer that contacts thetoilet 12. In one preferred arrangement, the sensor 70 is coupled to thebolt 17 connecting the tank 16 to the bowl 18 as shown in FIG. 1. Such aplacement is suitable for detecting vibrations and is also relativelyinconspicuous. However, other suitable placements of the sensor 70 arealso possible, such as when the system 10 is used with a monolithictoilet model in which the bowl and tank are formed as a single piece.

During the push cycle of a flush cycle, when the flapper valve 38 isopen and water is permitted to move from the tank 16 to the bowl 18through the passage 32, there are detectable parameters that canindicate an impeded flush. For example, if the siphon tube 22 were tohave some type of the impedance wherein the water 20 could not flow outof the bowl 18, when the water 20 begins to pass from the tank 16 to thebowl 18, the water 20 in the bowl 18 will begin to rise thus providing alarger than normal amount of water 20 in the bowl 18. In addition, thewater 20 may flow at a slower rate than normal from the tank 16 to thebowl 18, thus resulting in a slower rate of change of the water level inthe tank 16, which could be measured. Similarly, the rate of change ofthe pressure within the tank 16, or pressure differentials within thetoilet 12 (e.g., between the tank 16 and the bowl 18), may vary in animpeded flush condition from the values typical of a normal flushcondition. These differences as compared to a normal flush cycle havebeen discovered by the present inventors to affect certain parameters orcharacteristics of the toilet 12, including the vibrationalcharacteristics of the toilet 12. In such circumstances, the amplitudeof the vibration of the toilet 12 is decreased, possibly due to theincreased amount of water 20 in the bowl 18, the decreased flow rate ofthe water from the tank 16 to the bowl 18, among other possibilities. Itis possible that the decrease in amplitude is, in part, due to thedamping effect of the larger-than-normal volume of water 20 in the bowl18 in the event of an impeded condition. The above-described example iswith reference to an accelerometer that can measure amplitude ofvibration. As will be appreciated by one skilled in the art, otherparameters that can be detected may include frequency or othervibrational parameters that may be measured in the frequency and/or timedomains. Such alternative parameters can also be used to determine if animpeded flush condition exists.

One example of a vibrational signal 100 that is produced by a sensor,such as the sensor 70, during a flush cycle is illustrated in FIG. 3Aand FIG. 3B. The vibrational signal 100 shown in FIG. 3A and FIG. 3B isan amplitude versus time plot wherein the amplitude of the vibrationalsignal 100 oscillates over a period of time. In the particularillustrated embodiment, the time period over which the vibrationalsignal 100 is displayed is approximately 8 seconds, which is asufficient period of time to capture a typical push cycle portion of atoilet flush cycle. Experimentation has shown that a typical push cycleis about 6 seconds for toilets that are currently available for consumeruse. However, it will be understood that the push cycle time may beconsiderably longer, depending on the toilet type, especially oldertoilets that use, for example, 3-5 gallons of water per flush. Althoughsuch toilets are not currently produced, at least in significant volumesin the United States, the present system 10 may be used with, or adaptedfor use with, such toilets. Thus, the illustrated vibrational signal 100is an example of the typical vibrational signal over the entirety of thepush cycle of a flush cycle for toilets that have a push cycle of lessthan about 8 seconds. However, the system 10 may also be adapted for adesired time interval to correspond to a desired sensing duration.Accordingly, the system 10 can be adapted for the timing of a particularflush cycle. For example, because it is possible to accurately determinethe existence of an impeded flush condition in significantly less timethan a complete push cycle, some embodiments of the system or method mayutilize only a portion of the push cycle.

FIG. 3A illustrates a normal push cycle wherein the vibrational signal100, at least during a push cycle, maintains substantially the sameamplitude at each vibrational peak, or for each period. FIG. 3Billustrates a vibrational signal 100 of an impeded flush condition inwhich the peak amplitude of the vibrational signal 100 decreases overtime. The graphs of FIGS. 3A and 3B illustrate that, during a pushcycle, the peak amplitude is a parameter of the vibration of the toilet12 that is capable of being monitored to distinguish between an impededflush and a normal flush. Thus, the vibrational signal 100 can be usedto determine if the actuator 72 should be actuated in response to anyparticular flush cycle. In light of the present disclosure, it isapparent that multiple parameters may be satisfactory for use indistinguishing between a normal flush condition and an impeded flushcondition in addition to the peak amplitude of the vibrational signal100 specifically illustrated in FIGS. 3A and 3B. Some of the otherpossible determination criteria are discussed in greater detail below.

In another embodiment the sensor 70 can comprise an acoustic sensorthat, in some embodiments, may be placed on or adjacent to the toilet12. As will be appreciated by one skilled in the art, the vibrationsthat can be detected by an accelerometer will, in some embodiments, alsocreate an acoustic signal that can be measured with a transducer, suchas a microphone, much like the accelerometer measures vibration of thetoilet 12. Once again, in some embodiments, amplitude of the acousticsignal can be measured to determine if an impeded flow condition exists.Detecting acoustical vibrations can be particularly advantageous in thatthe sensor 70 can be placed in various different locations that are inaudible communication with the toilet 12. This can provide a wider rangeof sensing positions as compared to the vibrational sensing describedabove with reference to a vibration sensor, such as an accelerometer.

In another embodiment, the sensor 70 can comprise a flow rate sensorthat can measure certain flow parameters in the toilet 12 during a flushcycle. One example of a flow rate sensor that can be used to determine aparameter of a flush cycle is a flow rate sensor that monitors flowthrough the siphon tube 22 of the toilet 12. For example, if there is ablockage in the siphon tube 22, the flow rate of fluid within the toilet12, such as the flow rate through the siphon tube 22 or through thepassage 32 between the tank 16 and the bowl 18, is measurably reduced inmost toilets, thus indicating an impeded flow condition. Similar to thevibrational sensing method described above, the flow rate can bemeasured during a push cycle so that there is sufficient time to closethe flapper valve 38 and stop the push cycle prior to contentsoverflowing from the bowl 18.

In a similar variation of the system 10, an impeded flush condition maybe determined by measuring and analyzing a water level within the toilet12 and, in one arrangement, a change in the level of the water 20 in thetank 12 over time. In other words, the rate of the level change of thewater 20 in the tank 12 (e.g. water level drop) can be measured and themeasured values used to determine if an impeded flush condition exists.It is expected that the rate of water level change within the tank 12will be slower than normal if an impeded flush condition exists. Therate of change of the water level may be measured by any suitablesensor, such as a mechanical sensor (e.g. float), for example. Othertypes of sensors may be used as well. Such an arrangement has anadvantage that the water level rate of change may be more practical tomeasure than the water flow rate (described above) or pressure(described below).

In another embodiment, the sensor 70 can comprise a pressure sensorthat, similar to the sensor embodiments described above, can measurecertain parameters of a flush cycle that may be indicative of an impededflush condition. One example of a usage of a pressure sensor is to placea pressure sensor within the toilet 12, such as in the tank 16, bowl 18or passage 32 therebetween, to measure a pressure characteristic of afluid within the toilet 12 (e.g., water 20 or air). In such aconfiguration, in an impeded condition, the water 20 in the tank 16 maydrain at a slower rate than that of a normal flush, thus crating agreater head pressure for a longer period of time in the tank 16. Aswill be appreciated by one skilled in the art, a pressure sensor can beused in a variety of different capacities to detect an impeded flush.For example, it may be desirable to measure pressure differentials attwo locations within the toilet 12, and base the decision-making of thesystem 10 on a pressure differential, rather than on an absolutepressure value.

As discussed briefly above, the sensor 70, in many of its possibleembodiments, can be used to detect a parameter of a flush cycle that isindicative of an impeded flush. In some embodiments, the determinationof whether the detected parameter is indicative of an impeded flush or anormal flush is achieved by the processing of information gathered bythe sensor 70. For example, the signal produced by the sensor 70 may beprocessed by the processor 78 utilizing one or more algorithms thatcompare the sensed value of a parameter, or parameters, to the known orexpected value of the parameter(s) that are known to be indicative of animpeded flush and/or known to be indicative of a normal flush. That is,the data gathered by the sensor 70 preferably is used to determine ifthe flush cycle is impeded. FIG. 3A and FIG. 3B illustrate how, in oneembodiment, the condition of the flush cycle can be determined as aresult of sensed vibrations of the toilet 12.

As discussed above, FIG. 3A is a representation of a vibrational signal100 from the sensor 70. The vibrational signal 100 is plotted on anamplitude versus time plot such that time is plotted on the x-axis andthe amplitude of the vibration is plotted on the y-axis. Also plotted inFIG. 3A are an average peak value 104 and a threshold value 106. In theillustrated embodiment, the average peak value 104 is an average line ofthe peak values P1-P7 of the vibrational signal 100. The threshold value106 is an established value that can be compared to the average peakvalue 104 such that when the average peak value 104 drops below thethreshold value 106 an impeded flush is determined to be present. Thethreshold value 106 can be established through various methods includingthrough experimentation or through a calibration procedure, which isdescribed in greater detail below.

FIG. 3A illustrates a normal flush in which the average peak value 104does not drop below the threshold value 106 during the particular timeinterval of interest, which in some arrangements may include the entirepush cycle. In contrast, FIG. 3B illustrates an impeded flush in whichthe average peak value 104′ drops below the threshold value 106′ in theplotted time interval. Thus, as shown in FIG. 3B the vibrational signal100′ comprises peak values P1′-PT in which the latter peak valuesP5′-P7′ are below the threshold value 106′. That is, the average peakvalue 104′ that establishes a trend line for the peak values P1′-P7′drops below the threshold value 106′ thus indicating that an impededflush condition exists. In other arrangements, the system 10 may lookonly at the individual peak values, rather than an average of the peakvalues and determine that an impeded condition exists if any of the peakvalues drops below the threshold value 106′.

Although the vibrational signal 100 and 100′ illustrated on FIGS. 3A and3B is illustrated showing peak values P1-P7 and P1′-P7′, it will beappreciated by one skilled in the art, that various numbers of peakvales may exist for different vibrational signals. The illustratedvibrational signals 100 and 100′ are simply examples and are notintended to limit the scope of the present invention. Furthermore, dueto the variation of water dynamics in a toilet during different flushcycles, it is possible that no two vibrational signals will beidentical, although it has been determined by the present inventors thatthe vibrational signals for a particular toilet are consistent enough topermit the accurate distinction between a normal and impeded flushcondition.

With continued reference to FIG. 3A and FIG. 3B, the time interval shownin the plots, in some embodiments, can be predetermined so as to capturean appropriate timeframe to measure the vibrational signal of a pushcycle of a flush cycle. In the particular illustrated embodiment, thetimeframe is approximately 8 seconds, which generally can encompass anentire push cycle of a flush cycle. In many toilets, a push cycle willtake approximately 6 seconds, thus a timeframe of eight seconds, in manyembodiments, is sufficient to view the entire push cycle. As will beappreciated by one skilled in the art, other timeframes or time windowsmay be used, as described above, particularly in connection with toiletsthat have a push cycle time significantly longer than about 6 seconds.

Although the particular illustrated vibrational output shown in FIG. 3Ahas been illustrated wherein each of the peaks P1-P7 have beenillustrated as being above the threshold value 106, in otherembodiments, some of the peak values of the vibrational signal 100 mayfall below a threshold value 106 but may not indicate an impeded flush.That is, in some impeded flush determination methods, the peak valuesP1-P7 of the vibrational signal 100 may be allowed to fall below thethreshold value 106 for a certain period of time. This can be achievedby an algorithm that determines how many peak values have fallen below athreshold value in a certain amount of time. This can be particularlyadvantageous when a vibrational signal may produce some sporadic oroutlying peaks that may fall below a threshold value but may notnecessarily indicate an impeded flush condition. Thus, by providing atime constraint that requires the peak values P1-P7 (or average of thepeak values 104 and 104′) to fall below the threshold value 106 for acertain amount of time (e.g., the period T in FIG. 3B), the likelihoodof an incorrect determination of an impeded flush condition may bereduced. In other words, an algorithm may be used that requires the peakvalues P1-P7 to drop below the threshold vale 106 for a particularperiod of time T before an impeded flush is determined to be present.Other arrangements may determine that an impeded condition exists if aparticular number of consecutive peak values fall below the thresholdvalue 106. Other possibilities for determining that an impeded conditionexists from a sensed signal will be apparent to those of skill in theart in view of the present disclosure.

Although the illustrated example of FIGS. 3A and 3B involves determiningthe existence of an impeded flush condition by analyzing peak values ofa sensed vibration in comparison with a minimum threshold value, otheralgorithms may be used to analyze the sensed vibration and, moreparticularly, the output signal of the sensor 70. These algorithms mayalso be applied to any other sensed parameter or sensor output signal,regardless of type. For example, a frequency domain-type algorithm maybe used to analyze the sensor output including, without limitation, anFFT (Fast Fourier Transform), DCT (Discrete Cosine Transform), anothers. Time domain-type algorithms may be used, including, withoutlimitation, integral (e.g., integration of a real time signal),derivative (rate of change), running window, envelope detectors, varioustypes of filters (e.g., low, band or high pass), adaptive filters, etc.Moreover, combinations of time and frequency domain processing may beused, as taught by modern digital signal processing methodologies, aswill be apparent to those of skill in the art.

In some embodiments, the toilet overflow prevention system 10 can becalibrated for a particular toilet on which it has been installed. Thiscalibration can establish a threshold value that can be substantiallysimilar to the threshold value 106 and 106′ described above, to be usedto determine the condition of a flush cycle. In the illustratedembodiment, the toilet overflow prevention system 10 can be calibratedon a particular toilet such as the toilet 12 of FIG. 1 with one or moreknown normal flush cycles that can establish the threshold value 106 or106′ to which future flush cycles can be compared.

In one embodiment, after the toilet overflow prevention system 10 hasbeen installed on a particular toilet, one method to calibrate thesystem 10 can comprise the user activating a calibration mode of thetoilet overflow prevention system 10 such that the system 10 is alertedthat the flush or flushes that are soon to follow are calibrationflushes. One arrangement enters a calibration mode immediately uponfirst being turned on. During the calibration, a user preferablyactivates one or more flushes that are known normal flushes. Forexample, the user preferably visually verifies that the calibrationflushes are normal, or unimpeded. That is, the user can simply flush thetoilet at a time when it is known that no impedance will occur. Duringthe normal flushes, the processor 78 receives the output of the sensor70 that, in some embodiments, may produce an output similar to thesignal 100 shown in FIG. 3A. In one embodiment, an algorithm can beapplied such that a threshold value or range is determined from thepeaks P1-P7. That is, an algorithm can be used to establish thethreshold value 106 from the peak values P1-P7 such that the thresholdvalue 106 is set at a predetermined or calculated amount below the peakvalues P1-P7. After the establishment of the threshold value 106, thethreshold value 106 can be stored in a non-volatile memory (e.g., memory80) and used to compare to future flush cycles to detect an impededflush condition.

As will be appreciated by one skilled in the art, various differentalgorithms can be used to establish or calculate a threshold value thatthen distinguishes between a normal and an impeded flush for aparticular parameter. As noted above, certain other conditions may berequired to be present in order to determine that an impeded flushcondition exists, such as the values being below (or above) thethreshold value for a period of time or for a certain number ofconsecutive values. In addition to the algorithm described above, analternate algorithm may produce a range or envelope, having upper andlower limits, about a certain measured parameter so as to establish anormal operating range that can be compared to future flushes todetermine if an impeded flush condition exists.

One particular advantage provided by calibrating the overflow preventionsystem 10 after it has been installed on a particular toilet is thatmany of the operating parameters, including acoustic and vibrationalsignatures produced by a particular toilet, may be sensitive to thesurrounding environmental conditions. For example, a toilet installed ona concrete floor may produce a different vibrational signature than atoilet installed on a wood floor. Also, for example, a toilet installedin a large spacious room may have a different acoustic signature than atoilet installed in a small room or water closet. Thus, calibrating thetoilet overflow prevention system 10 after it has been installed in itsoperational location can provide a more accurate baseline fordetermining if a flush cycle is impeded.

As discussed above, however, the calibration of the toilet overflowprevention device can also be performed prior to installation. In someembodiments, tests can be performed to establish a set of predeterminedranges or values for a particular toilet or style of toilet such thatthe calibration procedure described above is not required. For example,if a group of toilets is to be installed under similar operatingconditions, the range of threshold values to determine if a flush cycleis impeded can be predetermined and preprogrammed so that the toiletoverflow prevention devices need not be calibrated after installation.Such a system may be pre-installed as a part of the original toilet, forexample.

FIGS. 4-6 are flow diagrams that illustrate preferred control methodsthat may be employed with some of the foregoing embodiments. In FIG. 4,a control method is provided for toilet overflow prevention. At block120, a flush cycle signature is detected that is produced by a parameterof a flush cycle of a toilet. As described above, this can be achievedin a variety of different ways including sensing vibration, an acousticsignal, a flow rate, flow level, or a pressure condition. At block 122the flush cycle signature is determined to be indicative of an impededflush condition. As described above, this determination can be achievedby an algorithm that, in some embodiment, may be executed in a processorsuch as the processor 78 of FIG. 2. At block 124, an activation signalis sent to an actuator in response to the impeded flush condition,wherein the actuator is able to implement or initiate a substantialreduction of flow of water to the toilet bowl. As described above, theactuator 72 is configured to receive a signal in response to a detectedimpeded flush condition. As is discussed in greater detail below, oneembodiment of such an actuator is described with reference to FIG. 7 andFIG. 8.

FIG. 5 illustrates a method for determining that an impeded flowcondition is present. At block 126, a parameter that is caused by waterdynamics within the toilet is sensed. As described above, the parametercan be sensed in a variety of different ways including sensingvibration, an acoustic signal, a flow rate, or a pressure condition. Thewater dynamics produce detectable parameters that can be analyzed todetermine the existence of an impeded flow condition. At block 128, aparameter value of the water dynamics is compared to a normal range ofthe parameter value. As described above, the normal range can bedetermined through a variety of different ways, including throughcharacteristics of the toilet or through a calibration procedure. Atblock 130, it is determined that an impeded flow condition exists if theparameter value is outside the normal range. As described above, thedetermination can be performed by an algorithm in the processor 78.

In FIG. 6, a preferred method for calibrating a toilet overflowprevention device is illustrated. At block 132, a parameter is sensedfor one or more known flush cycles of the toilet, wherein the normalflush cycle includes a push cycle. At block 134, a representative rangeis established using the parameter that was sensed at block 132. Atblock 136, the range is stored in the memory for later comparative use.

FIG. 7 and FIG. 8 illustrate one embodiment of the actuator 72. Theactuator 72 is generally configured to be attachable to an overflow tubesuch as the overflow tube 56 illustrated in FIG. 1. The actuator 72preferably is capable of receiving a signal, which is at least in partgenerated by the sensor 70 and which may be processed by the processor78. The actuator is generally configured to forcibly close the flappervalve 38 so as to inhibit or entirely stop the flow of water through thepassage 32 from the tank 16 to the bowl 18. In the particular embodimentillustrated in FIG. 7 and FIG. 8, the actuator 72 is configured to pushdown the flapper valve 38 via a weight dropping mechanism, which isdiscussed in greater detail below.

The actuator 72 includes a main housing 202 that preferably is agenerally tubular member that houses, at least in part, an inner hammerrod 204 and an outer hammer rod 206. the inner hammer rod 204 and theouter hammer rod 206 are configured to be axially movable within themain housing 202. The inner hammer rod 204 carries a hammer weight 208that is attached to the lower end of the inner hammer rod 204. The mainhousing 202 also includes an overflow tube attachment structure 210 thatallows the actuator 72 to be secured to the top of the overflow tube 56so as to position the actuator 72 above the flapper valve 38.

With continued reference to FIG. 7, the upper portion of the mainhousing 202 preferably includes a solenoid assembly 212 that isconfigured to selectively restrain or release the outer hammer rod 206,which in turn restrains or releases the hammer weight 208. The solenoidassembly 212, in some embodiments, comprises a solenoid 214 that isconnected to a solenoid latch 216 that defines a mechanical catch tohold or release the outer hammer rod 206. As discussed briefly above,the solenoid 214 can be actuated by a control signal that may be sent bythe sensor 70 or processor 78. The solenoid 214 may receive a controlsignal via a hardwired signal or a wireless signal, such as an RFsignal, for example.

The actuator 72 preferably is configured to hold the hammer weight 208in an elevated position relative to the flapper valve 38 such that theflapper valve 38 is free to move between its open and closed positionsduring normal flush cycles. In the illustrated embodiment, after theactuator 72 has received an appropriate control signal, the solenoid 214activates the solenoid latch 216 to release the outer hammer rod 206. Asa result, the outer hammer rod 206, and thus the hammer weight 208, arereleased and fall downward under their own weight to forcibly close theflapper valve 38. As discussed above, the detection, processing andrelease of the hammer rod 206 preferably occurs before the entire flushvolume of water is evacuated from the tank 16.

The actuator 72 preferably is configured to have a predetermined amountof stroke for the outer hammer rod 206 relative to the main housing 202.That is, the outer hammer rod 206 generally determines the amount ofmovement that the hammer weight 208 will have based on the length of theouter hammer rod 206 and the length of the main housing 202. In someembodiments, it is preferable that the hammer weight 208 will be loweredto a sufficient height so as to securely close the flapper valve 38. Inthe illustrated embodiment, a certain amount of telescopic adjustabilityis provided between the inner hammer rod 204 and the outer hammer rod206.

With continued reference to FIG. 7, the inner hammer rod 204 preferablyis insertable into the outer hammer rod 206 and telescopicallyadjustable so as to adjust the height of the hammer weight 208 relativeto the height of the overflow tube 56. The inner hammer rod 204preferably is securable relative to the outer hammer rod 206 by a rodcollar 218 that can be tightened to secure the inner hammer rod 204 in adesired position relative the outer hammer rod 206.

Also included in the actuator 72 is a reset latch 220 that is configuredto be manually lifted to reset the actuator 72 after the hammer weight208 has been released by the solenoid latch 216. As will be appreciatedby one skilled in the art, in other embodiments, the actuator 72 can beconfigured to automatically reset after the hammer weight 208 has beenreleased, thus negating the need for the reset latch 220.

With reference to FIG. 8, the actuator 72 is secured to the top of theoverflow tube 56 via the overflow tube attachment structure 210, whichis configured to be a snap-fit in the illustrated arrangement.Furthermore, the main housing 202 of the actuator 72 preferably ispositioned such that the hammer weight 208 is located generally abovethe flapper valve 38 such that when the hammer weight 208 is released,it will drop on the top of the flapper valve 38 and forcibly close theflapper valve 38.

With continued reference to FIG. 8, the hammer weight 208 is shown beingsupported in a height set jig 222 which is configured to allow a user toset the height of the hammer weight 208 relative to the outer hammer rod206 (and the flapper valve 38). After the actuator 72 has been installedon the overflow tube 56, a user preferably loosens the rod collar 218thus allowing the inner hammer rod 204 to move axially relative to theouter hammer rod 206. At this time it is preferable that a user placethe hammer weight onto the top of the height jig 222 wherein the legs224 of the height jig 222 are resting on the bottom of the tank 16. Atthis time while the hammer weight 208 is being supported by the heightjig 222, a user then preferably tightens the rod collar 218 to securethe inner hammer rod 204 relative to the outer hammer rod 206 thussetting the proper height of the hammer weight 208. Before the system 10is placed into use, the height jig 222 preferably is removed.

Although one particular embodiment of the actuator 72 has beenillustrated with reference to FIG. 7 and FIG. 8, as will be appreciatedby one skilled in the art, various other embodiments of actuators can beused to substantially reduce or eliminate water flow to the bowl in 18in the event of a detected impeded flush condition. Such suitablealternative embodiments may comprise an actuator 72 that independentlyrests on the bottom of the tank 16 and does not attach to the overflowtube 56. Other suitable embodiments may comprise an actuator that isattached to the upper rim of the tank 16. Another suitable embodimentmay comprise a rotational solenoid attached to the flapper valve 38 suchthat a torsional force is applied to the pivoting arm of the flappervalve 38 so as to close the flapper valve in the event of an impededflush condition. Another embodiment may not comprise an actuator locatedin the tank 16 but may include an actuator that is attached a valve thatcontrols water flow from the external water supply source 44 asillustrated in FIG. 2. Thus, the actuator 72 shown in FIG. 7 in FIG. 8is simply one possible embodiment of an actuator that can be used withthe toilet overflow prevention system 10.

Although this invention has been disclosed in the context of certainpreferred embodiments and examples, it will be understood by thoseskilled in the art that the present invention extends beyond thespecifically disclosed embodiments to other alternative embodimentsand/or uses of the invention and obvious modifications and equivalentsthereof. In addition, while the number of variations of the inventionhave been shown and described in detail, other modifications, which arewithin the scope of this invention, will be readily apparent to those ofskill in the art based upon this disclosure. It is also contemplatedthat various combinations or subcombinations of the specific featuresand aspects of the embodiments may be made and still fall within thescope of the invention. Accordingly, it should be understood thatvarious features and aspects of the disclosed embodiments can becombined with, or substituted for, one another in order to performvarying modes of the disclosed invention. Thus, it is intended that thescope of the present invention herein disclosed should not be limited bythe particular disclosed embodiments described above, but should bedetermined only by a fair reading of the claims.

1. A toilet overflow prevention system for use with a toilet,comprising: a sensor capable of detecting vibration of the toilet duringa flush cycle, said sensor generating a signal indicative of saidvibration; a processor that receives said signal from said sensor,processes said signal to determine if said vibration is indicative of animpeded flush condition and generates a control signal in response to animpeded flush condition; and an actuator that receives said controlsignal from said sensor and in response to said control signal operatesto close a valve, which stops a flow of water within the toilet.
 2. Thetoilet overflow prevention system of claim 1, wherein said processorcompares a value of a parameter of said signal to a normal range of saidvalue stored in said memory to make said determination of an impededflush condition.
 3. The toilet overflow prevention system of claim 2,wherein said processor compares said value of said parameter to saidnormal range over a period of time.
 4. The toilet overflow preventionsystem of claim 3, wherein said period of time is sufficient to includean entire push cycle of the flush cycle.
 5. The toilet overflowprevention system of claim 3, wherein said processor makes saiddetermination of an impeded flush condition if said value iscontinuously outside of said normal range for a time interval.
 6. Thetoilet overflow prevention system of claim 2, wherein said normal rangeis preprogrammed.
 7. The toilet overflow prevention system of claim 2,wherein said normal range is determined through a calibration cycle. 8.The toilet overflow prevention system of claim 1, wherein said sensor issecured to a body of the toilet to directly sense vibration of thetoilet.
 9. The toilet overflow prevention system of claim 8, whereinsaid sensor is an accelerometer.
 10. The toilet overflow preventionsystem of claim 8, wherein said sensor is secured to a fastener thatconnects a tank to a bowl of the toilet.
 11. The toilet overflowprevention system of claim 1, wherein said actuator closes a flappervalve of the toilet.
 12. The toilet overflow prevention system of claim11, wherein said actuator comprises a weighted member, said weightedmember being releasable to fall onto the flapper valve in order to closethe flapper valve.
 13. A method of calibrating a system for detecting animpeded flush of a toilet comprising sensing the value of a parameter ofone or more normal flush cycles of the toilet and establishing a normalrange for the value of the parameter using the sensed value.
 14. Themethod of claim 13, wherein the establishing of the normal rangecomprises setting one limit of the normal range.
 15. The method of claim13, further comprising storing the normal range in a memory forcomparison to a value of the parameter during subsequent flush cycles.16. The method of claim 13, wherein the parameter comprises an amplitudeof a vibration of the toilet caused by fluid dynamics during the flushcycle.
 17. The method of claim 16, wherein the sensing of the amplitudeof the vibration is performed using an acoustical sensor.
 18. The methodof claim 13, wherein the parameter comprises a pressure differential ofa fluid within the toilet.
 19. The method of claim 13, wherein theparameter comprises a fluid flow rate within the toilet.
 20. The methodof claim 13, wherein the parameter comprises a fluid level rate ofchange within the toilet.